Sports shoe sole

ABSTRACT

A shoe sole comprising a sole portion (10) with a forward toe end (12) and a rear end (13), an inner medial side (15) and an outer lateral side (16). Blade-like projections (20) extend downwardly from the sole portion (10) and are angled relative to a generally longitudinal line (31) from the toe end (12) to the rear end (13) of the sole portion (10) so that an outer end (31) of each projection nearer to the medial side (15) is located nearer to the toe end. The angled projections provide increased grip for the outside foot of a wearer during turning movement. The heights of the projections (20) progressively reduce from the rear end (13) of the sole portion towards the toe end (12). At least the forwardmost one (21) of the medial projections has an outer corner (33) at the end of the lower extremity (30) which is displaced inwardly towards the lateral side (16). A transverse flexing zone (50) extends across the sole portion (10) at the location of the ball of the foot, and a longitudinal flexing zone (19) extends along the general center line (18) of the sole portion (10) from the toe end (12) to the rear end (13). The projection (23) at the ball of the foot includes a front face (42) which is upright to assist penetration of the projection (23) into the ground and to provide grip in use, the opposite face (41) of the projection (23) being inclined so that the projection progressively thickens towards the sole portion (10).

This invention relates to shoe soles, more particularly a sports shoesole comprising a front sole portion and usually a heel portion, atleast the front sole portion having projections extending downwardlyfrom the shoe sole.

Shoes having soles of the type defined above are well known for use insports where it is necessary to have good grip on a grass playingsurface, for example all football games. One problem with shoe soles ofthis type is that under muddy conditions they become blocked with mudand lose their effectiveness to provide grip. The standard boot withscrew-in studs often presents the wearer with turning difficulties andis known as a source of knee injury.

It is an object of the present invention to significantly reduce thesedisadvantages.

According to the present invention there is provided a shoe solecomprising a sole portion with a forward toe end and a rear end, aninner medial side and an outer lateral side, the shoe sole furtherincluding a plurality of blade-like projections extending downwardlyfrom the sole portion, each projection extending downwardly to anelongated and relatively thin lower extremity, at least two of theprojections being medial projections which extend from the vicinity ofthe medial side of the sole portion towards the lateral side and atleast a further two of the projections being lateral projections whichextend from the vicinity of the lateral side of the sole portion towardsthe medial side, at least one of the medial projections being angledrelative to a generally longitudinal line from the toe end to the rearend of the sole portion so that an outer end nearer to the medial sideof the sole portion is located forwardly of a centre end of the angledprojection remote from the medial side of the sole portion, the angledmedial projection thereby providing increased grip for the outside footof a wearer during turning movement as a result of extending normal toor being relatively close to being normal to the direction of pushingforce on the angled medial projection during such turning movement.

The expressions "inner medial side" or "inner medial edge" of the soleportion are used to refer to the side of the sole portion which isnearer to the sole portion to be worn on the other foot of the user.Thus, looking down on the right shoe being worn on the foot, the "innermedial side" and "inner medial edge" of the sole portion will be at theleft side, and vice versa.

Each projection has a height defined as the distance from the soleportion to the lower extremity and the height of the projections nearerto the toe end may be less than the heights of those projections closerto the rear end. Preferably the height reduction is progressive towardsthe toe end. This improves the "feel" during running.

At least one of the medial projections and preferably the ones nearestthe toe end, may have an outer corner at the end of the lower extremitywhich is nearer to the medial side of the sole portion which isdisplaced towards the lateral side of the sole portion and away from theline of the medial side. This enables a ball to be kicked with theinside of the foot so as to loft the ball without the medial projectionsstriking the ball first.

There may be provided a transverse flexing zone across the sole portionat the location of the ball of the foot, the transverse flexing zone nothaving any projections thereon nor containing portions of anyprojections. This construction enables the sole portion to bend acrossthe ball of the foot thereby enabling the foot to bend along its naturaltransverse flexing line.

In one possible embodiment suitable for most sports, each of the medialand lateral projections is angled obliquely across the sole portion withthe end of each projection nearer to the medial side being locatedforwardly and closer to the toe end of the sole portion.

In an alternative possible embodiment suitable particularly for sportsin which there is much forward pushing or forward acceleration, at leastone of the medial projections and at least one of the lateralprojections may extend transverse and normal to the general longitudinalline of the sole portion, the medial and lateral projections normal tothe longitudinal line being located towards the toe end of the soleportion forwardly of the angled projections whereby forward force at thetoe end of the sole portion is borne by the projections normal to thelongitudinal line.

The projections are described as "blade-like" because when viewed inunderneath plan, they do not appear circular like standard stops orstuds, or even square, but are elongated and relatively thin. Theaverage length of the parallel or long sides of each projection isalways larger than the average width of the projection.

The advantage of these blades is that they are more easily pushed intothe ground to provide grip. They also provide a large area to pushagainst when orientated generally transverse to the direction of pushingforce.

A standard stop is rounded and cuts its way through the ground offeringleast resistance. This is a disadvantage to the wearer since maximumgrip is desirable. The blade-like projection gives far more grip than astandard round stop, when orientated so its largest cross-sectional areais generally normal to the direction of travel or of pushing force. Onereason is because the cross sectional area being pushed against can be,for example about twice that of a standard stop. This characteristic isutilised in the preferred embodiment to give superior grip.

Possible and preferred features of the present invention will now bedescribed with particular reference to the accompanying drawings.However it is to be understood that the features illustrated in anddescribed with reference to the drawings are not to be construed aslimiting on the scope of the invention. In the drawings:

FIG. 1 shows underneath plan views of left and right soles according tothe invention, the blade-like projections being a mirror image on eachshoe,

FIG. 2 shows a view of the medial side of the left shoe showing how theprojections gradually decrease in height as they near the toe end,

FIG. 3 shows a view of the angled or chamfered blade-like projections tohelp with a kicking action common in soccer,

FIG. 4 shows a perspective view from the medial side of the left shoesole from near the toe end depicting the various side profiles of theblade-like projections,

FIG. 5 shows the heel section on which two blade-like projectionsintersect to form a cross shape, the ends of the cross extend to theedges of the sole, and the projections tapering into the sole,

FIG. 6 shows a view of the removed parts of the taper on two of theprojections on the lateral side of the sole, so as to improve the gripof the projections during turning,

FIG. 7 shows the transverse zone created by removal of some of the taperfrom the projection at the ball of the foot, this zone flexing of thesole across the ball of the foot, and

FIG. 8 shows in underneath plan view a shoe sole according to analternative possible embodiment.

The shoe sole in the drawings comprise a sole portion 10 with a forwardtoe end 12 and a rear end, an inner medial side 15 and an outer lateralside 16. The sole also includes an integral heel portion 11. A pluralityof blade-like projections 20 extend downwardly from the sole portion 10.Each projection extends downwardly to an elongated and relatively thinlower extremity 30. Three of the projections 21, 22, 23 are medialprojections which extend from the vicinity of the medial side 15 towardsthe lateral side 16. Three of the projections 20 are lateral projections24, 25, 26 which extend from the lateral side 16 towards the medial side15. In the embodiment of FIGS. 1 to 7, the medial projections 21, 22, 23are angled relative to a generally longitudinal line 18 from the toe end18 through the rear end 13 of the sole portion to the heel portion 11 sothat the outer end 31 nearer to the medial side 15 is located forwardlyof the centre end 32 of the angled projections remote from the medialside 15. With this feature, the angled medial projections 21, 22, 23provide increased grip for the outside foot of a wearer during turningmovement as a result of extending normal to or being relatively close tobeing normal to the direction of pushing force "A" on the angled medialprojection during such turning movement.

The projections 20 increase in thickness as they approach the surface ofthe sole 10 eventually merging into the sole. The sole 10 andprojections 20 are moulded in one piece so that the tapering of eachprotrusion 20 gives maximum strength to the protrusion and prevents apotential split line being created at the join of the sole and theprojection. Rubber or a plastics material is preferred for the shoesole.

The rate of increase in thickness of the projections 20, while beinggenerally similar, may vary from blade to blade and even from one sideto another on some projections. This variation is because theprojections need to have sides as steep as possible to penetrate theground and give grip, but they also need support so they do not bend andbuckle under the pressure of running and turning.

As best illustrated in FIG. 4, most projections 20 have faces 40 whichthicken towards the sole portion with a profile which is generallyhyperbolic or parabolic with the maximum steepness being at or close tothe lower extremity 30 so that the faces of the blades at the lowerextremities are the closest to being normal to the general plane of thesole portion 40. This is true all the way along the height of theblades. The only time it is possible to deviate from this is in the topmillimeter or so (near the edge coming in contact with the groundfirst), because by then the amount that the rubber can bend isinsignificant.

The formulae describing the hyperbolae or parabolas on the blades 20 mayvary from blade to blade and side to side because of the various rolesthey play in running and turning and the various pressures exerted onthe blades. In one possible embodiment, projection 23 includes a face 42which is substantially upright relative to the general plane of the soleportion 10 to thereby assist penetration of the projection 23 into theground and to provide grip in use. The face 41 of the projection 23opposite to the upright face 42 is inclined so that the projectionprogressively thickens towards the sole portion 10. The inclined face 41has a generally parabolic or hyperbolic profile. The projection 23having the one upright face 42 and the one inclined face 41 has itsinclined face 41 facing towards the heel portion 11.

The blade 23 having the one upright face 42 and the opposite inclinedface 41 is the projection located on the sole portion 10 generally atthe ball of the foot of the wearer. This projection 23 comes under themost pressure during turning. This projection 23 is substantiallythickened on the side 41 closest the heel 11 so it does not buckle. Tocompensate, its other side (facing the toe) is almost

normal to the sole 10, to maximise the projection's penetration andgrip. Each of the projections 21, 22, 24-26 have opposite faces whichboth taper at generally similar rates so as to define the thickening ofthe projections towards the sole portion 10.

The only variation to this may be on the projection 26 transverselyopposite the one 23 at the ball of the foot. The heel face 43 of thatprojection 26 does not come into play when sprinting, so it can betapered slower to more closely match the projection 23 at the ball ofthe foot.

Alternatively, in an embodiment not illustrated, the projections mayslope at a generally constant angle to the general plane of the soleportion so as to define the thickening of the projections towards thesole portion. But this is inferior in design as it gives less grip as itis preferable to have as much of the blade normal to the sole aspossible to give the maximum grip.

The medial projection 21 as shown in FIG. 3 has an outer corner 33 atthe end of the lower extremity 30 which is nearer to the medial side 15of the sole portion 10. The outer corner 33 is displaced towards thelateral side 16 of the sole portion and away from the line of the medialside 15. In the illustrated embodiment the medial projection 21 has anouter end 31 extending from the outer corner 33 to the sole portion 10,the outer end 31 being inclined to the general plane of the sole portion10 so that the outer end 31 extends substantially from the medial edge15 of the sole portion 10.

The medial projection 21 is nearest to the toe end 12 of the soleportion whereby a shoe having the sole portion 10 secured thereto can beused to strike a ball with the inside of the foot without the medialprojection 21 striking the ball before the inside of the foot.

To explain this further, there is a particular kicking action in soccerthat relies upon the inside of the footwear coming into contact with theball. In particular, the foot may need to be angled to reach under theball and impart loft. If the projection 21 at the forward end and at theinside, i.e. nearest to the major toe, extends in the medial directionto be generally immediately vertically below the inner edge 15 of thesole portion 10, the point 33 of that projection 21 at its lowerextremity would contact the ground or the ball first and may limit theability of the user to place the foot under the ball to produce thedesired loft.

In the illustrated embodiment, the projection 21 nearest to the toe end12 of the sole portion 10 and at the medial side 15 of the sole has itsouter edge tapered or chamfered. The second medial projection 22counting from the toe end 12 of the sole portion also has an outercorner displaced laterally away from the medial side 15 of the soleportion and towards the lateral side 16.

It is possible to replace the two projections 21, 22 nearest to themajor toe at the medial side 15 with conventional stops, although thisis not the preferred design. This is not preferred because the bladelike projections have significant advantages in respect to grip, mudremoval and turning that make them superior to conventional stops. Thisis so even though the blade like projections may be smaller in areanearer to the major toe.

As shown in FIG. 2, the heights of the projections 21, 24 nearer to thetoe end 12 are less than the heights of those projections 23, 26 closerto the heel end 11. The reason for this height reduction is to improvethe weight transfer during the running action. The decreasing heightstowards the toe end 12 result in a smoother running action. In thepreferred embodiment, the heights of the projections progressivelyreduce from the rear end 13 of the sole portion towards the toe end 12.

This effect of a variation in height could also be achieved by theinsertion of a wedge of padding placed under the sole from heel to toe,but it is more costly and not as effective for soft grassed conditions.Use of a wedge under the heel or heel and arch does work well. In thiscase, the blades desirably still vary in height to get the best weighttransfer effect.

Except for the problem of getting the toe part of the inside of the footwell under the ball, it is preferred that the lower extremities 30 ofthe blades 20 extend the full way to the inner and outer edge 15, 16 ofthe sole portion 10. This is to maximise the width of the sole incontact with the ground. This gives a broader base and a more stablefeel to the wearer. Therefore, all the projections 23-26 not havingouter corners 33 displaced laterally extend at their lower extremities30 substantially completely to the line of the adjacent edge 15, 16 ofthe sole portion 10. The outer side 31 of the blade adjoining the edgeof the sole portion can have some taper to make it easier to be pulledfrom the mould during manufacture. This can mean a slight loss of widthacross the sole if measuring from lower extremity of blade to lowerextremity of blade but the effect should not be significant enough to benoticed by the wearer.

Having the ability to flick mud off the sole is one of the advantages ofthis style of boot. Aspects affecting this include the flexing of thesole which is preferably of rubber or suitable plastics material, thespacing between the projections 20 and the amount of space in the centreof the sole unoccupied by projections 20. This last feature issignificant and so that the ends of the projections 20 remote from theadjacent edges 15, 16 of the sole portion 10 and closer to the generallongitudinal centre line 18 are inclined relative to the general planeof the sole portion 10 thereby facilitating removal of mud from the soleportion during use.

The shoe sole 10 includes a longitudinal flexing zone 19 (see FIG. 1)extending along the general centre line 18 of the sole portion from thetoe end 12 to the rear end 13. The longitudinal flexing zone 19 containsno portions of any projections 20 so that the sole portion 10 can flexalong the general centre line enabling the projections on opposite sidesof the longitudinal flexing zone 19 to move apart slightly during suchflexing and enable mud to be dislodged from the shoe sole in use.Continuous blades extending across the sole angled on the same lines asthe blades are not as effective in soft muddy conditions since too muchmud sticks. To further assist longitudinal flexing, the relatively longprojections 23, 26 at the ball of the foot may be split mid way alongtheir length and substantially throughout their height.

The angles on the sides 32 facing the zone 19 need not be precise andangles between 30 and 60 degrees work satisfactorily.

In FIG. 7 a transverse flexing zone 50 extends across the sole portion10 at the location of the ball of the foot. The zone 50 does not haveany projections 20 thereon nor contains portions of any projections.This enables the sole portion 10 to bend across the ball of the footenabling the foot to bend along its natural transverse flexing line. Inmost movements, the foot needs to bend across the ball of the foot. Theblades 20 provide a strong resistance to bending, so if they arepositioned in this zone 50, they resist bending on the natural flexingline, making the sole feel more rigid to the user and restrictingperformance.

In the illustrated embodiments, the heel 11 has two long blades 53, 54that are crossed. The cross shape of the heel blades on the heel 11provides more grip and stability than the standard studs. These blades53, 54 are also tapered for the same reasons stated for the blade-likeprojections on the sole portion 10. The ends of the cross blades 53, 54on the heel 11 extend all the way to the edge of the heel to provide thewidest and most stable base to the wearer. Studs or other projectionsmay however be used on the heel.

In FIG. 2, a lip 55 is added around the heel and/or toes so the sole canbe sewn onto the upper 56. This lip 55 is angled normal to the surfaceof the sole and is used to wrap around the upper. Another lip 58 mayextend along the lateral and/or medial side at the instep. Such lips arecommon on many jogging shoes. The lips facilitate a stronger bondingbetween upper 56 and sole 10. This lip can also broaden the sole byabout 4 to 5 millimeters. The same features described still hold withthe blades in this case. So, the blades, including those on the heel,still preferably extend all the way to the edges of the sole.

In the preferred embodiment, of FIGS. 1 to 7, each of the medial andlateral projections 20 is angled obliquely across the sole portion 10with the end of each projection nearer to the medial side 15 beinglocated forwardly and closer to the toe end 12 of the sole portion 10.The angled projections can extend at an angle between 35 and 55 degreesto the longitudinal line 18 from the toe end to the rear end. Each solein FIG. 1 is a mirror image of the other.

With this invention, there is more grip on the outside foot duringturning. This is because at least the medial projections 21-23 will beangled normal or closer to normal to the desired direction at the stresspart of the turn. This provides the maximum surface area being normal tothe direction of momentum of the body, for the wearer to push againstand so provide the wearer with grip to perform the turn. Conversely, theother foot (which will be on the inside during the turning action) willhave at this time all its blade-like projections orientated in the samedirection as travel at this part of the turn (as it is a mirror image ofthe other foot). While still providing some grip, the inside soleprovides less grip than the outside foot during the turn. The result ofthe variation in grip is a differential turning effect like on a racingcar. The turning is then smoother and more efficient. This effect canalso help in injury prevention as the wearer's weight distribution ismore correct with more pressure being on the outside leg during theturn.

In the preferred illustrated embodiments, there are six blades 20 on thesole section 10 of the foot arranged to avoid the pressure points on thefoot. With the six blades arranged this way, the pressure is adequatelyspread and substantial grip is provided.

In the preferred embodiment, the blades are in pairs transversely acrossthe foot to balance the foot and give stable support. In one possibleembodiment (FIG. 6), at least one 26 of the 10 lateral projectionscloser to the rear end 13 of the sole portion than the toe end 12increases in thickness from the lower extremity 30 towards the soleportion, the increase in thickness of the projection being lesser at anouter end 60 of the projection 26 closer to the lateral edge 16 of thesole portion 10 so as to promote greater penetration of the ground bythe outer end 60 of the projection at the lateral edge 16 of the soleportion during sharp turning action.

Preferably there are two such blades, being the second 25 and third 26counting from toe 12 to heel 11. The taper may be trimmed on the outeredge 60 of the heel side of the projection. This improves penetrationand grip. This may be needed as sometimes in a sharp turning action,e.g. if a player is turning right, those two projections 25, 26 on theright foot might be all that is in the ground, as the player leans over.

In a second possible embodiment shown in FIG. 8, the shoe sole 10 hastwo of the medial projections 121, 122 and two of the lateralprojections 124, 125 extending transverse and normal to the generallongitudinal line 18 of the sole portion. The medial and lateralprojections 121, 122, 124, 125 normal to the longitudinal lines arelocated towards the toe end 12 of the sole portion forwardly of theangled projections 123, 126 whereby accelerating force at the toe end 12of the sole portion 10 is borne by the projections 121, 122, 124, 125normal to the longitudinal line 18. This embodiment is particularlysuited to sports in which there is much forward force at the toe end ofthe sole, e.g. as a result of pushing in rugby scrums or in gridiron, orwhere rapid forward acceleration is more common and frequent thanturning. The angled blades 123, 126 at the ball of the foot assistturning as in the first embodiment.

The thickness 70 of the protrusion 123 at the ball of the foot may beminimised at its inner end nearer the axis 18 while being thickened forstrength towards the medial side 15. This is to minimise the amount ofnon bending area of the sole in this important bending zone. Theprotrusions will not flex as the sole flexes. This modified shape ofprotrusion 123 may be used instead of the shape of protrusion 23 inFIGS. 1 to 7.

It is to be understood that various alterations, modifications and/oradditions may be made to the features of the possible and preferredembodiment(s) of the invention as herein described without departingfrom the scope of the invention as defined in the claims.

I claim:
 1. A shoe sole having a forward toe end and a rear heel end,said sole divided into a half sole which includes said forward toe end,and a heel portion which includes said rear heel end, said half solehaving an inner medial side and an outer lateral side wherein alongitudinal line runs along the center of said half sole and liesbetween said inner medial side and said outer lateral side, wherein theportion of said sole between said longitudinal line and said innermedial side defines an inner portion of said half sole and the portionof said half sole between said longitudinal line and said outer lateralside defines an outer portion of said half sole,at least a pair ofelongated medial projections having a length and a width, each of saidmedial projections having an outer end adjacent said medial side and anopposite inner end, at least a pair of elongated lateral projectionshaving a length and a width, each of said lateral projections having anouter end adjacent said lateral side and an opposite inner end, each ofsaid projections extending downwardly from said sole and terminating inan elongated narrow lower edge having a length many times greater thanthe width thereof, the inner end of each of said projections extendingdownwardly from said sole and outwardly away from said longitudinalline, the outer end of each of said projections extending downwardlyfrom the associated adjacent side and inwardly toward said longitudinalline such that the length of each of said projections tapers from alarger dimension at said sole to a smaller dimension at the lower edgethereof, the outer end of each of said lateral projections extendingdownwardly directly from the associated adjacent side, each of saidprojections having a forward surface and a rearward surface, saidforward surface extending downwardly from said sole and away from saidtoe end, said rearward surface extending downwardly from said sole andaway from said heel end such that the width of each of said projectionstapers from a larger dimension at said sole to a smaller dimension atthe lower edge thereof, the inner ends of each of said projections atsaid sole being spaced a substantial distance from said longitudinalline in a direction extending laterally of said longitudinal line andtoward the associated adjacent side so that said longitudinal line isfree of projections and a vacant space is provided along saidlongitudinal line, said medial projections being angled such that theouter ends thereof are closer to the toe end than the inner endsthereof, said lateral projections being angled such that the inner endsthereof are closer to the toe end than the outer ends thereof, theangled medial and lateral projections thereby providing increased gripfor the outside foot of a wearer during turning movement.
 2. A shoe soleas claimed in claim 1, wherein each projection has a height defined asthe distance from the sole to the lower edge and the heights of theprojections closer to the toe end are less than the heights of theprojections closer to the heel end.
 3. A shoe sole as claimed in claim2, wherein the heights of the projections progressively reduce from theheel end of the sole towards the toe end.
 4. A shoe sole as claimed inclaim 1, wherein the outer end of at least one of the medial projectionsis displaced away from the medial side to define a displaced outer end.5. A shoe sole as claimed in claim 4, wherein said medial projectionhaving said displaced outer end has its inner end inclined to thegeneral plane of the sole portion relative to said displaced outer end.6. A shoe sole as claimed in claim 4, wherein the medial projectionclosest to the toe end is displaced from the medial side of said halfsole so that a shoe having the sole secured thereto can be used tostrike a ball with the inside of the foot without the medial projectionclosest to the toe end striking the ball before the inside of the foot.7. A shoe sole as claimed in claim 6, wherein a second medial projectioncounting from the toe end is also displaced from the medial side of saidhalf sole so that a shoe having the sole secured thereto can be used tostrike a ball with the inside of the foot without the second medialprojection striking the ball before the inside of the foot.
 8. A shoesole as claimed in claim 1, wherein each of said lateral projections hasan outer corner at its lower edge which extends to the lateral side ofsaid half sole.
 9. A shoe sole as claimed in claim 1, wherein atransverse flexing zone is provided across the half sole at a locationsuch that when attached to a shoe the flexing zone is provided at theball of the foot of the wearer, said transverse flexing zone being freeof projections and portions of projections thereby enabling the halfsole to bend across the ball of the wearer's foot and allowing the footto bend along its natural transverse flexing line.
 10. A shoe sole asclaimed in claim 9, wherein the half sole includes a longitudinalflexing zone extending along the longitudinal line from the toe end tothe heel end of said sole, the longitudinal flexing zone being free ofprojections and portions of projections so as to enable the sole portionto flex along the longitudinal line such that projections on oppositesides of the longitudinal flexing zone are able to move slightly apartfrom each other during flexing thus enabling mud to be dislodged fromthe shoe sole in use, each of said projections of said half sole beingangled along an axis wherein all of the axes of the projections of saidhalf sole are parallel to each other.
 11. A shoe sole as claimed inclaim 1, wherein each of the medial and lateral projections is angledobliquely across the sole portion with the end of each projection closerto the medial side being located forwardly and closer to the toe endsuch that when a wearer turns so as to change to a new direction offorward motion the projections on the sole of the outer foot areelongated in the new direction of forward motion.
 12. A shoe sole asclaimed in claim 1, further including at least one transverse medialprojection and at least one transverse lateral projection which extendtransverse and substantially perpendicular to the longitudinal line, thetransverse medial and transverse lateral projections being locatedtowards the toe end and closer to the toe end than the angledprojections whereby an accelerating force at the toe end of the halfsole is borne by the transverse projections.
 13. A shoe sole as claimedin claim 1, wherein the projections extend at an angle between 35 and 55degrees to the longitudinal line from the toe end toward the heel end.14. A shoe sole as claimed in claim 1, wherein each projection inelevation is generally trapezium shaped, and the lower edge of eachprojection is substantially parallel to the half sole.
 15. A shoe soleas claimed in claim 1, wherein the half sole, the heel portion and theprojections are molded in one piece and each projection increases inthickness from its lower edge toward the sole.
 16. A shoe sole asclaimed in claim 1, wherein at least one forward or rearward surface ofat least one projection has a profile which is generally hyperbolic withthe maximum steepness being adjacent the lower edge thereof.
 17. A shoesole as claimed in claim 1, wherein at least one forward or rearwardsurface of at least one projection has a profile which is generallyparabolic with the maximum steepness being adjacent the lower edgethereof.
 18. A shoe sole as claimed in claim 1, wherein one forward orrearward surface of at least one of the projections slopes at agenerally constant angle relative to the general plane of the half sole.19. A shoe sole as claimed in claim 1, wherein at least one of theprojections has its forward or rearward surface situated substantiallyperpendicular relative to the general plane of the half sole to therebyassist penetration of the projection into the ground and to provide gripin use, and wherein the opposite surface thereof is inclined.
 20. A shoesole as claimed in claim 19, wherein the last-mentioned projection hasits inclined face facing generally away from the toe end of the halfsole and towards the heel end.
 21. A shoe sole as claimed in claim 19,wherein the last-mentioned projection is the projection located on thehalf sole closest to the ball of the foot of a wearer.
 22. A shoe soleas claimed in claim 21, wherein each of the projections other than theprojection closest to the ball of the foot has its forward and rearwardsurfaces tapering at generally similar rates.
 23. A shoe sole as claimedin claim 1, wherein said heel portion also has projections to engage andgrip the ground.